Hartford Air Quality in 2020
In 2020, Hartford's air quality (Hartford-West Hartford-East Hartford, CT area) had a median daily AQI of 43 (Good) across 366 monitored days. 2 days (0.5%) reached Unhealthy for Sensitive Groups or worse, 245 were Good, and the year's peak AQI was 129 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 191 of those days. The cleanest month of 2020 was September (median AQI 36, 0 days above 100) and the worst was July (median 52, 1 day above 100, peak 129).
- Good: 66.9%
- Moderate: 32.5%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
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How was Hartford's air quality in 2020?
Good on a typical day: median AQI 43, with 2 days above AQI 100 out of 366 monitored — the 1st cleanest of 7 years on record for the area.
- ✓Peak AQI in 2020: 129 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 191 days.
- ✓Cleanest month: September; worst: July.
Frequently asked questions
What was the average AQI in Hartford in 2020?▾
EPA's Air Quality System puts Hartford's (Hartford-West Hartford-East Hartford, CT) median daily AQI for 2020 at 43, which is Good. 2 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 129.
Which month had the worst air quality in Hartford in 2020?▾
The cleanest month of 2020 was September (median AQI 36, 0 days above 100) and the worst was July (median 52, 1 day above 100, peak 129).
Was 2020 a good or bad year for Hartford's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 1st cleanest by days above AQI 100 — the best year on record here. 2020's median of 43 is in line with the area's typical annual median of 43.
Hartford month by month in 2020
Hartford air quality month by month, 2020 (Hartford-West Hartford-East Hartford, CT, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 45 | 0 | 84 | PM2.5 |
| February | 29 | 52 | 0 | 71 | PM2.5 |
| March | 31 | 41 | 0 | 60 | O3 |
| April | 30 | 42 | 0 | 54 | O3 |
| May | 31 | 41 | 0 | 84 | O3 |
| June | 30 | 51 | 0 | 97 | O3 |
| Julyworst | 31 | 52 | 1 | 129 | PM2.5 |
| August | 31 | 51 | 1 | 101 | O3 |
| Septembercleanest | 30 | 36 | 0 | 84 | O3 |
| October | 31 | 38 | 0 | 55 | PM2.5 |
| November | 30 | 46 | 0 | 98 | PM2.5 |
| December | 31 | 40 | 0 | 98 | PM2.5 |
How 2020 compares
Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 1st cleanest by days above AQI 100 — the best year on record here.
2020's median of 43 is in line with the area's typical annual median of 43.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Hartford
The latest EPA AirNow observation puts Hartford's AQI at 19 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Hartford air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Hartford-West Hartford-East Hartford, CT), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.